Deranged 44-year-old Marie Moore believed she was the Antichrist acting on the Devil’s orders.

She took 20-year-old son Mitchell to the Shoot Straight range in Florida for what he thought was an afternoon’s practice.

But when he turned to aim at a target, his mum picked up a revolver and blasted a single bullet into the back of his skull at point-blank range. As he slumped to the floor she put the gun in her mouth and pulled the trigger.

A suicide note read: “I’m so sorry. I had to send my son to Heaven and myself to Hell.”

Moore had spent long stints in psychiatric hospitals and suffered hallucinations.

Questions are being asked as to how she was allowed to rent guns. She had been barred from the range after attempting suicide there seven years ago.